mongoDB for sysadmins

Jordi Soucheiron - @jordixouSoftware developer & sysadmin @ DEXMA

@sudoersbcn 2013/6/4

What is mongoDBDocument oriented noSQL database

Auto sharding -> scales horizontally

Auto replication -> high availability

Atomic in-place updates

No transaction support

JSON queries and results

Open source with commercial support by 10gen

What is it used for?Storing files

Storing logs

Queue systems

Data mining

…

Basic mongoDB setup

Pros: Simple

Cons: No sharding, no high-availability

Small mongoDB setup

Pros: High-availability, optional delayed node

Cons: No sharding

Advanced mongoDB setup

Advanced mongoDB setupPros:

High-availabilityReads and writes are distributed amongst all

nodesYou choose what kind of replication you wantYou choose what collections are shardedYou choose the sharding key

Cons:More complexity than the other solutionsYou ALWAYS want 3 config servers

Demo time

Configure VagrantInit Vagrant:

Modify Vagrantfile:Vagrant.configure("2") do |config| config.vm.box = "precise64" config.vm.box_url = "http://files.vagrantup.com/precise64.box" config.vm.provision :puppet do |puppet| puppet.manifests_path = "manifests" puppet.manifest_file = "init.pp" endend

vmvagrant init precise64 http://files.vagrantup.com/precise64.box

Configure Puppetmkdir Manifests

vi init.pp:

package { 'mongodb':ensure => present,

}

Start Vagrant and mongoDB

vagrant up

vagrant ssh

sudo /etc/init.d/mongodb stop

mkdir –p ~/mongo/db1 ~/mongo/db2 ~/mongo/db3

mongod --port 27017 --dbpath ~/mongo/db1 --replSet rs0 --smallfiles --oplogSize 128 --rest

mongod --port 27018 --dbpath ~/mongo/db2 --replSet rs0 --smallfiles --oplogSize 128

mongod --port 27019 --dbpath ~/mongo/db3 --replSet rs0 --smallfiles --oplogSize 128

Add nodes to the replica set

mongo --port 27017

rsconf = { _id: "rs0", members: [ { _id: 0, host: "127.0.0.1:27017" } ] }rs.initiate( rsconf )rs.add("127.0.0.1:27018")rs.add("127.0.0.1:27019")

Questions